Human cerebellum: its parts and functions

What is the cerebellum and what are its functions within the central nervous system?

The cerebellum is much more than a sort of little brother of the neocortex, tucked half-hidden between the occipital lobe and the brainstem. In fact, this curious structure resembling a flattened ball of wool is one of the most important parts of the brain.

Indeed, it is considered that in most cases the proper functioning of the cerebellum is indispensable for our survival and cases in which this rule is not met become news.

Although it is an apparently quite discreet structure, as it is partly hidden by the cerebral cortex, the cerebellum is one of the most important structures of the brain, the cerebellum is one of the areas of the brain with the highest density of neurons.. In fact, approximately half of the brain's neurons are located in this structure. But... Why is it so important for the cerebellum to be in good condition? What processes is it responsible for?

The functions of the cerebellum

For many years now the function of the cerebellum and the coordination of Muscle activation have been related for many years.. Thus, the task of the cerebellum was basically considered to be to enable us to maintain our balance, to coordinate simple and complex movements and, in general, to ensure that the muscles of our body respond faithfully and effectively to the commands issued by the brain.

For example, one of the main symptoms of cerebellar disturbances used to be loss of balance after drinking too much alcohol. However, in recent years it has been discovered that the idea that the role of the cerebellum is related to motor coordination is too simplistic. Thus, the cerebellum is not only involved in motor processes, but also plays an important role in many other functions..

The cerebellum in the regulation of emotions

One of the connecting pathways of the cerebellum links this structure with large areas of the limbic system, which is related to the emergence and maintenance over time of the emotional states that color our experiences. As it is in communication with structures such as the amygdala, the cerebellum has the capacity to intervene in the regulation of the emotional states that appear in the cerebellum..

Thus, for example, part of the functions of the cerebellum have to do with creating associations between sensations and feelings, which serves as a support for future learning by relating certain experiences with specific feelings.

The cerebellum and cognitive processes

The fact that the cerebellum has such a density of neurons and that it is connected to large areas of the cerebral cortex makes the idea that it has something to do with cognitive processes such as memory or attention management not sound far-fetched. There is currently some research pointing in that direction.

For example, it has been shown that the size of the cerebellum may be related to the level of intelligence one has.. In addition, from studies in which the effects that a lesion in the cerebellum has on the mental capacities of patients are observed, it has been possible to relate dysfunction in this structure with attention deficits and the use of language.

The tricky thing about investigating this is that from these studies based on cases of cerebellar injury it is not possible to know whether the decrease in cognitive abilities is due to the fact that the neurons involved in them have died (being located in the area of the injury) or whether these effects are due to an imbalance in the functioning of the brain caused by the injury. Thus, much more research is needed, much more research is needed to know whether the role of the cerebellum in cognitive functions is as important as these studies seem to suggest.

The cerebellum and motor coordination

The old ideas about the role of the cerebellum as a center for the coordination of muscle activation have not been refuted. Today, this structure is still considered to play a leading role in the coordination of movements, maintenance of balance and monitoring of neuronal signals aimed at activating muscles.

As the cerebellum is connected to many areas of the brain, it cross-checks the motor information elaborated in the higher regions of the brain with the more "concrete" and operational motor information aimed at activating muscle fibers, and verifies that there are no inconsistencies between the two. In addition, there is a debate generated around the possibility that one of the functions of the cerebellum is motor learning, i.e., the ability to go to the higher regions of the brain to activate muscle fibers.that is, the ability to polish a pattern of movements so that it becomes more and more refined.

Structure of the cerebellum

The cerebellum may be relatively small, but its composition is very complex.. Although one can talk at length about the different parts and subdivisions of the parts of the cerebellum, on this occasion we will focus only on the broadest categorization of the structures of the cerebellum, i.e., the parts that can be easily seen with the naked eye (provided one has a cerebellum in front of one's eyes, of course).

The hemispheres of the cerebellum

The cerebellum is similar to the rest of the brain in that it is also covered by a layer of cells that create a rough, folded surface. However, in the case of the cerebellum, these folds are even tighter and thinner, as can be seen with the naked eye. That is why one of the structures or subregions of the cerebellum is known as the cerebellar cortex..

The cerebellar cortex is divided into two cerebellar hemispheres, just as the cerebral cortex is divided into a right and a left hemisphere. In the middle of these hemispheres lies a region called the vermiswhich is a vertical strip that joins both parts and connects them to each other.

The lobes of the cerebellum

Beyond this classification of parts of the cerebellar cortex, there are several lobes of the cerebellum, just as each hemisphere of the cerebral cortex is divided into lobes of the cerebrum. These lobes are the anterior lobe, the posterior lobe, and the flocculonodular lobe, arranged from superior to inferior.